This project is concerned with the studies of the binding of hemoglobin to red cell membranes using fluorescence probes. Two classes of binding sites with different affinities have been identified. Studies of mutant hemoglobins have revealed a 'new' example of Hb Koln and another unstable hemoglobin now under investigation. Kinetic studies of nitrosylhemoglobin and mixed ligand species indicate a high degree of cooperativity in the dissociation of NO from Hb4(NO)4. Clinical and kinetic studies are being carried out on glycosylated hemoglobin. BIBLIOGRAPHIC REFERENCES: Shaklai, N., Yguerabide, J. and Ranney, H.: Binding of hemoglobin to the red blood cell membrane as shown by a fluorescent chromophore. Fed. Proc. 36: 271A, 1977. Sharma, V.S. and Ranney, H.M.: Allosteric equilibrium between R and T forms of nitrosylhemoglobin: A kinetic study. Fed. Proc. 36: 890A, 1977.